1231540400 has 60 divisors (see below), whose sum is σ = 3003001992. Its totient is φ = 485253120.

The previous prime is 1231540357. The next prime is 1231540403. The reversal of 1231540400 is 40451321.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is not an unprimeable number, because it can be changed into a prime (1231540403) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 3824 + ... + 49776.

Almost surely, 2^1231540400 is an apocalyptic number.

1231540400 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1231540400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1501500996).

1231540400 is an abundant number, since it is smaller than the sum of its proper divisors (1771461592).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1231540400 is a wasteful number, since it uses less digits than its factorization.

1231540400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 46038 (or 46027 counting only the distinct ones).

The product of its (nonzero) digits is 480, while the sum is 20.

The square root of 1231540400 is about 35093.3099037409. The cubic root of 1231540400 is about 1071.8883590206. Note that the first 3 decimals are identical.

Adding to 1231540400 its reverse (40451321), we get a palindrome (1271991721).

The spelling of 1231540400 in words is "one billion, two hundred thirty-one million, five hundred forty thousand, four hundred".